The invention relates to the field of intraluminal catheters, and more particularly to a guiding catheter having a deflectable distal end.
Guiding catheters are used in many percutaneous intravascular procedures to guide diagnostic and therapeutic devices or fluids, and the like, to a desired location within the patient. For example, a guiding catheter is typically used in conjunction with balloon catheters used in angioplasty procedures and electrophysiology (EP) devices used for ablation or mapping of cardiac tissue. U.S. Pat. No. 5,509,411, incorporated by reference (Littmann et al.) is an example of an EP catheter.
In the design of guiding catheters, different and often competing considerations relating to catheter flexibility and strength must be balanced. The guiding catheter proximal section must have sufficient flexibility and strength to be advanceable and torqueable, and have sufficient column strength to limit shaft buckling. The distal end of the guiding catheter is typically more flexible than the proximal section, to provide maneuverability and to prevent trauma to the patient's vasculature. However, the distal end must have sufficient strength to prevent kinking during advancement.
While a large delivery lumen is desirable for delivering devices such as EP catheters, the outer diameter of the catheter must be minimized so that the catheter can be readily advanced within the patient. Therefore, when the catheter contains a large delivery lumen, the walls of the catheter are necessarily thin in order to minimize the outer diameter of the guiding catheter. Typically, a tubular or braided metal line reinforcement may be provided within a wall of the catheter. The line reinforcement stiffens the catheter and transmits torque to the catheter distal end as the proximal end of the catheter outside the patient is rotated .
The distal end of the guiding catheter frequently needs to be bent or shaped while within the patient. The bent shape is useful in guiding the catheter distal end into a desired body lumen or chamber. For example, during an EP ablation or mapping procedure, the guiding catheter must be maneuvered through a patient's branched vasculature to advance an EP device into a patient's coronary sinus. Moreover, the shaped or shapeable distal end of the guiding catheter is used to orient the distal tip of the EP device with respect to tissue, such as a patient's endocardium, to facilitate proper delivery of the device's RF or laser energy to the tissue. Consequently, the guiding catheter may be provided with a preformed distal tip which may be guided into the desired location in the patient by rotating the proximal end of the guiding catheter from outside the patient. Additionally, the guiding catheter may be provided with a deflection mechanism to reversibly deflect the distal tip while within the patient.
One difficulty has been providing a deflectable guiding catheter having sufficient column strength and torque transmission in combination with a relatively large lumen for delivering devices such as EP catheters. Moreover, many prior deflectable catheters are typically limited to uniplanar deflection, which requires the catheter shaft to be rotated from its proximal end located outside of the patient in order to place to deflected tip into a desired plane, as, for example, to place the distal tip of the catheter into a desired branched vessel or in contact with a desired tissue wall.
What has been needed is a catheter with a kink resistant, torqueable, and deflectable shaft which nonetheless defines a large unobstructed lumen for receiving a device therein. The present invention satisfies these and other needs.